Homebrew PCBs

D@^# I typed a lot of replies this evening!

>In Homebrew_PCBs, Stefan Trethan <stefan_trethan@g...> wrote:
> 
> I did exactly that and you are correct...
> A later post shows that orcad is just fine.

Yep. saw that.

>I hope you have read the "place cutoff stips of reels to one side of 
>the cnc, hold by pegs" thing. i think it is a good idea, what do you 
>think?.

A good idea to use the less than full reels? Definitely. We are a 
hobby and small shop group, after all. But I'll use the machine to 
index even these short tapes, so the pickup point is the same for 
each part at a given "tape slot". Something perhaps non-obvious to a 
new cnc user is that the machine can do things in unusual ways. For 
instance, motion can be programmed to "press a button" before trying 
to pick up the part. The button can be ANYWHERE that ANY part of the 
machine can reach... So you might not "press it" with the z axis, but 
perhaps simply be moving the machine gantry to a certain place. This 
movement hits the switch to index the tape/reel. You could also use 
the needle of the vacuum pickup itself and an optical switch, firing 
a "one shot" in your macro... or in external hardware... Lotta ways 
to "skin this cat"...   

>I do no longer think the pick and place file is impossible, it is 
>slightly more difficult than paste dispensing (because you have to 
>fetch the parts)but it is not undoable.

Exactly. Doing it is pretty easy. Doing it WELL is quite a bit 
tougher... And solder paste dispensing is EASY by comparison. 


Ballendo